This invention relates generally to systems and methods for enhancing hearing in patients suffering from sensorineural hearing loss.
Hearing loss is frequently categorized as being either xe2x80x9cconductive hearing lossxe2x80x9d or xe2x80x9csensorineural hearing lossxe2x80x9d. Conductive hearing loss typically refers to middle ear impairment and generally results from damage to the tympanic membrane and/or middle ear ossicles. Sensorineural hearing loss is frequently attributable to a reduction in function of hair cells within the cochlea. When sufficiently severe, sensorineural hearing loss can be mitigated by implanting electrodes in the cochlea to electrically stimulate the auditory nerve. When less severe, hearing loss can be mitigated by enhanced activation of the middle ear mechanism. For example, the prior art describes various electrically driven actuator devices for physically contacting and mechanically vibrating the middle ear ossicles.
Great strides have been made in the development of cochlear implant systems for restoring hearing in people suffering from severe sensorineural hearing loss. Such systems are typically comprised of an implant housing containing implant electronics for driving an array of electrodes which are surgically inserted into the cochlea. The implant electronics are typically driven by sound processing electronic circuitry which is generally, but not necessarily, contained in a housing worn externally by the patient. A microphone carried by the patient supplies electric signals to the input of the sound processing circuitry. Typical sound processing circuitry and implant electronics provide for multiple frequency channels.
The present invention is based on the recognition that existing cochlear implant technology, and particularly devices presently available for implanting in the cochlea to stimulate the auditory nerve, can alternatively be advantageously used in the middle ear to activate the ossicles.
Accordingly, the present invention is directed to a middle ear system comprised of cochlear implant electronics implanted in the middle ear and coupled to an actuator configured to mechanically vibrate the ossicles. A middle ear implant system in accordance with the invention is useful for amplifying sound for patients having reduced, but sufficient, cochlear function.
In accordance with the present invention, implant electronics typically used for driving an electrode array implanted in the cochlea, is used instead to supply electric drive signals to an actuator capable of physically contacting and mechanically vibrating the ossicles. In the case of multichannel implant electronics, it is generally sufficient to map the output drive signal for a single channel to the entire frequency spectrum for driving the actuator.
By combining available technology and devices presently used to electrically stimulate the auditory nerve with existing middle ear actuators, an improved middle ear implant system is provided.
Because middle ear systems in accordance with the invention take advantage of electronic and mechanical design developments from a related but distinct application area, i.e., cochlear implant technology, they can be rapidly and cost effectively provided in accordance with the invention.